The ST and DT series of
continuous ESD monitors are new and improved designs over the
AEI-920xD series monitors. The new circuits allow for improved
manufacturing and specifications while still providing low cost
products. They also provide more trouble free operation with fewer
false alarms due to operator movement and wrist strap handling.

The ST series monitors are
Single Threshold units like the AEI-920x series. They detect when
the input at the wrist strap connection is above the high
resistance threshold or above the body capacitance spec. The
DT series monitors also detect when the input to the wrist strap is
below the Low threshold.